1. Field of the Invention
The invention relates to a method and device for disc rotation control in an optical storage system, more particularly to a method and device for disc rotation control in an optical storage system based on detected extent of disc warping.
2. Description of the Related Art
An optical disc is prone to warp due to numerous factors, such as manufacturing errors, prolonged exposure to humidity or sunlight, applied forces or pressure, etc. As shown in FIG. 1, when loaded on a tray 40 of an optical storage system, a warped optical disc 2 will not lie flat on the tray 40. Hence, due to positional imbalance of the optical disc 2 relative to a rotary axis thereof, a lot of noise and vibrations will be generated during high-speed rotation of the optical disc 2. As a result, the service lives of a spindle motor and the associated servo mechanism of the optical storage system are shortened, and stability of disc recording and playback operations are adversely affected. Moreover, manufacturers are mandated to produce optical storage systems that comply with specified allowable noise and vibration levels during disc recording and playback operations.